Cathode-ray oscillograph device



R. J. DIPPY CATHODE-RAY OSCILLOGRAPH DEVICE l nven [or @www SDW Hy @aww/ww, Mann/4- A I forney `Fume 27, 1950 Original Filed March 1'7, 1944' 3 Sheets-Sheet 2 R. J. DIPPY CATHODE-RAY OSCILLOGRAPH DEVICE jMl inve/:lor mw/ Attorney @amm June 27, 1950 Original Filed March 17, 1944 `Fune 27, 1950 R. J. DIPPY A2,512,923

CATHODE-RAY OSCILLOGRAPH DEVICE Original Filed March 17, 1944 3 Sheets-Sheet 3 I nvenfor B @mm Mwave/#Mb Attorney iPatented June 27, 195() ,sinn

CATHODE-RAY GSCILLOGRAPH DEVICE cember 23, 1942 Section 1, Public Law 690,fAugust;8, 194.6 Patent expires December 23,1962

14 Claims.

vThis .invention relates to cathode ray oscillograph devices -and is more particularly concerned With such devicesemploying a repetitive time-base operating to display a repetitive ap- ,pliedsignal input which represents .the subject under investigation.

One object of the inventionis to providean arrangement permitting the examination of one or more selected portions ofthe main or principal display on the oscillograph screen at a magnified time-base Writing speed.

Another object of the invention is to provide an arrangement in which a single cathode ray ltube may be used to display a large sectionof the repetitive signal input or y.alternatively to .display, to a .magnied.scale, any selected smaller portion of said `larger display.

Another object of the .invention is to provide anarrangement by which a marking indication is. givenon the main display and is adjustable in position therealong and in Which an alternative higher speed and therefore magnied time scale displaymay be provided ofthe marked portions .of 4said Amain display.

A further object of the invention is to provide ,an arrangement in which time marking or` calibration signals are provided on .themain display for assessment of the time period -of any loccurrence .indicated by the-display and .by which lthe same time marking signals are also available on a higher speed time-base delay of a selected .portion of saidv main display.

A further object of the invention is to provide an ,arrangement particularly suitable for use in wirelesssystems for the navigation of a mobile craftgas described in 4my copending application Serial No. 527,018 from which this presentapplication forms a divisional application.

.In order that the invention may be more clearly understoodone embodiment thereof, as applied to the Wireless `navigation system described in my co-pending application Serial No. 527,018 from which the pre-sent application forms a divisional application, Will now be described by .Way of example with reference to the accompanying drawings in Which- Figure .1 is a block diagram illustrating the main elements of a receiver as used in the aforesaid copending application Serial No. 527,018 and comprising a cathode ray oscillograph device `according to the present invention.

Figure 2 is a circuit diagram showing one arrangement vfor developing aplurality of marking signals by which marking indications may be providedandby Which the higher speed time- Ybases may be controlled.

2 `Figure 3 illustrates certain `operatingpotential wave-forms encounteredV in the `,circuit diagram vofligure 2 and Figures 4 and`5 showthe `appearance of the in- -put `signals and marking V.inclications'on the indicator tube in vthe initialse'tting and`^hi`gher speed vtime-base vconditions respectively.

In ymy aforesaid copending .application Y'Serial No. 527,018 -there isdescribeid a Wireless navigaries of positions where the time-intervals between pulse signals from the main station andthe counterpart signals'from the `tvvo satellite stations have a particular and constant value; by providing ya mobile craft, vsuch .as an aircraft, with means. for measuringthese time-intervals it is possiblel for the operator at such' craft to plot .his position, and, if necessary, to'navigate to- Wards any desired destination.

Referring now to Figure l1 ofthe drawings, incoming signals `at the mobileV craft are fed from an aerial AR to a receiver R from which they are passed directly. to one of the vertical deflecting plates y of a cathode-ray indicator `tube T, Where they cause a vertical displacement ofthe tube beam Whenever signals occur.

A crystal oscillator VC provides an outputat kc./s., Which is fed toa series-of divider stages DVI DVl Where frequency reductionto'500 C. P. S. is effected. The 500 C.P. S. output from DVI is applied through a diode V2 to a` switch 'STI Aby whichit can vbe fed to a saW-tooth'waveform generator V3 Whose output is passedbyway ofpush-pull ampli-fiers Vil, V5 to the horizontal deecting plates a: of the indicator tubeT, to ,causehorizontal scanning of the tube beam at 500 times per second.

The 500 C. P. Sroutput from divider stage DV'I is also applied yto a further frequency divider stage Vl' which providestwo output square-Waveforms, each of 250 C. P. S. but with one-phase displaced by v degrees, with respect to .the other. One of `these l250 C. P. S. square-Waveforms is applied to valve stages V7, V8 and `V9 and the other to valve stage VIU. Valvestage-Vl is arranged. in a manner described indetail flater,

3 to develop a three-step voltage output Wave-form which is applied to the vertical deflecting plate y of the indicator tube T, opposite to that supplied with input signals from receiver R, to cause Vertical displacement of the traces by the tube beam. Two of these voltage steps occur during the first-cycle of the 250 C. P. S. input waveformv and the third during the second half cycle. As horizontal scans are being provided by the generator V3, one during each half-cycleoi the 250 C. P. S. input to valve stage VI, the resultant display upon the screen of the indicator tube -T is a stepped upper trace and a further unstepped lower trace parallel therewith .as shown in Figure 4. Upon these traces the incoming signals appear as vertical deilections in the manner also shown in Figure 4.

The crystal oscillator VC is stabilized at its frequency of 150 kc./s., i. e. the same frequency as the master control oscillator of the A station described in my copending application Serial No. 527,017, and so serves as a synchronisingmedium between the pulse-recurrence frequency of the fixed transmitting stations and the scanning frequency of the present apparatus whereby a stationary or substantially stationary presentation of the received signals is provided by successive traces on the indicator tube T. A small degree of manual control of the frequency of the oscillator VC is desirable to allow for compensation of any slight change that may take place in either oscillator and also to provideI means whereby an intentional drift may be imparted to the positiony of the received signals upon the traces of the in' dicator tube T in order to bring such signals to particular positions most convenient for measurement purposes.

Measurement of the spacing and hence the,A

time intervals between the various received sigoscillator VC is taken in sharpened pulse form from a suitable point of the circuit of the divider stage DVI through valve stage DVS to the cathode of the indicator tube T to cause a series of brightened spots at intervals of 1/150000 sec. T0 facilitate counting, these are divided into groups of 10 and 100 by means of furthermarks derived from a, 15 kc./s. output taken from divider stage DVZ, DV3, and from a 1.5 kc./s. output taken froindivider stage DV5. These output are fed through valve stage DVS to the cathode of the indicator tube as with the 150 kc./s. time-markers and appear as additional brightened spots P (shown more clearly in Figure 5) immediately behind each tenth mark of the next smaller subdivision. In Figs. 4 and 5 of the drawings these brightened spots P are shown, for the purpose of illustration only, as vertical lines in view of the impossibility of depicting the variation of light intensity which occurs in actual practice. In practice with the main time-base display as Shown in Figure 4 the 150 kc./s. timemarkers would be too close-spaced to be distinguishable and are therefore not supplied, only the 15 kc./s. time-markers, divided into groups of ten by the 1.5 kc./s. time-marker appearing. On the highspeed time-bases described later, the 150 kc./s.

. time-markers appear as unit intervals sub-dividing the spaces formed by the 15 kc./s. time-markers as shown in Figure 5. i

Valve stages V8, V9 and VI D are arranged in A marker portions.

comprising three negative-going square-shaped pulses repeated at 250 C. P. S. As described in detail later these pulses may be adjusted as to their respective timing positions and by application to the cathode of the indicator tube T cause further brightening of selected short portions of the traces, hereinafter referred t0 as strobe The same three-pulse waveform output from VI I is connected to switch STI and may be used instead of the 500 C. P. S. output from divider DVl to trigger the saw-tooth generator V3 and hence to provide three (high speed) scans corresponding in time to those strobe marker portions of the main trace selected by adjustment of Ytiming of the aforesaid three negative-going pulses. As both the received signals and the vertical shift voltages from valve V'I continue to be applied to the indicator tube the re-n sultant display is one of three parallel scans as shown in Figure 5, providing in greatly magnified form the three selected strobe marker portions of the main trace shown in Figure 4.

Impulses from the generator V3 are applied to the control grid of the indicator tube T to suppressI the return stroke of the saw-tooth waveform providing the time-base scan in each case.

The signal receiver circuit R is preferably of the superheterodyne type and may take any convenient standard form. Similarly, the frequency dividing circuitsV DVI DVT and master crystal oscillator circuit VC may be of any known convenient type.

The circuits for producing the required strobe marker portions of the time-base may conveniently make use of the known properties of a pentode valve arranged as a transitron flipilop oscillator, i. e. having a negative mutual conductance characteristic between its suppressor and screen grids. If such a valve is initially biassed to out off at its control grid and is" then triggered by an applied puls'e the anode and screen grid voltages alternate between clear cut values, the duration of the cycle being controlled by the time constant of the feed-back coupling capacity between screen and suppressor grids and an associated leak-resistance.

Referring now to Figure 2, which shows a suitable circuit, a 250 C.y P. S. square wave output from the frequency divider stage VI (Figure l) and shown by the waveform. I, Figure 3, is applied to the control grid of a pentode valve V1. During each negative-going half-cycle of the applied wave-form, the valve V1 is cut off and in consequence both screen and anode potentials will be at a value approaching that of the HT+ supply line. Upon the arrival of a positive-going half-cycle of the applied waveform, space current will commence to flow and both screen and anode potentials will momentarily start to fall. Due, however, to the capacitive feed-back between screen and suppressor grids, the latter ywill itself be lowered in potential to divert space current from the anode to the screen grid with consequent increased fall of Vscreen potential. 'y Thisy further fall is again fedback to the suppressor to cause, in known manner, a precipitate change to the condition where the screen is taking all the space current and the anode is cut off by the suppressor. As a result the anode potential is maintained at its previous high value while the screen potential falls rapidly as depicted in waveform 2 (Figure 3) by the portions a-b. The level b is maintained until the suppressor grid potential rises, by discharge of the feedback lcapacity through resistanceR'I 'and potentiometer P1, to

a Value .permitting .anodecurrent k.to flow. .m.- mediatel-y. this takes place :the diversion `o'fcspace current to :the `anodefcauses a decrease vof vscreen current with Vconsequent rise of screen potential. This -`rise is fed back to the suppressor grid. to cause further increase in yanode current at the expense of the. screen current and` by a reversal ofthe `process described above causes a precipitate change to the condition where the division of spacecurrent between anode and screen is determined by the standing potentials of the valveyelectrodes. 'This r-ise -efrscreen vpotential is depicted by vthe portion c-d of waveform 2 (Figure 3'). Thesefconditions prevail over the `period d-e -of-waveform 2 (Fig-ure 3) until `the valve is against cut off completely by arrival of the following negative-going halt-cycle of` the input Wave whereupon the screen potential rises to its initial value and remains there throughout the negative-going half-cycle, i. e. over the period f-g of waveform 2 (Figure 3) until the arrival ofthe nextV positive-going half-cycle of the input Waveform initiates a repetition of events a described.

The threevoltage levels b-c, d-e and f--g constitute the necessary shift voltages for e'ecting vertical displacement of the trace upon the indicator tube T of Figure 1 and are accordingly f ed to the appropriate plate y by way of the condenser CI, potentiemeter P8 and switch SSI when inthe position shown in Figure 2.

Inthe arrangement described the potentiometer 'P1 controls the standing suppressor grid potential and the discharge time Aof the feedback ,capacity between screen and suppressor grids andV therefore determines both the length and the level of the portion d--e of the waveform '2 (Fig. 3). Potentiometer P8 determines the proportion ofthe developed voltage changes actually applied .as deflecting voltages to the indicator tube T and therefore controls the actual spacing between the traces.

With switch` SSI inthe opposite position to that` shown in Figure 2 potentiometer P8 is rendered'. inoperative and a different proportion. of the developed voltage changes is applied to the indicator tube T. As this lproportion will be less than any provided by setting `of. .potentiometer P8, la closing up of the trace spacing willresult for a purpose described later.

`Since the input Waveform to valve V1 is of 250. C. P. S. frequency Whereas the saw-tooth voltages provided by generator V3 through push- ,pull amplier V4, V5 (Figure l) are at 500 C. P. S., it will be clear that therst or positive-going portion 4(af-waveform I (Figure 3) will correspondv to .one horizontal trace provided by V3.V and the negative-going half-cycle of waveform I (Figure 3) lto the following horizontal trace from V3. As a resultthe voltage levels bc, de of Waveform 2y (Figure 3) will determine therelative lengths and vertical displacements of the top Step and remainder of the rst trace, whilst the voltage level ,fg determines the length and relative displacement of the second trace. With switch SSI in the position shown in Figure 2 the resultant appearance at the indicator tube T vwill be .as shown in Figure 4l while with the switch.. in the opposite position closing up of .thetracelevels occurs as shown in Figure 5.

Thesame 250 C. P. S. waveform I (Figure 3) is also applied'to the control grid of a second pentode valveVB. arranged as a transitionflipflop`r oscillator in similar manner. to V.,andac cordingly there is produced at its anode, a Ypotentialwaveform asishownlrat 3 (Figure-.3); alii this Waveform the small pip h correspondrto the momentary; drop in ;anode.potential` :upon initial :opening: up ot the valve .by (application of.:..the.:positive-going half-.cycle .of .the.ir1put Waveform to-its' :control:l grid. .and .the .levelqfhe-.i to .the immediately. followingperiod 4 when.; ithe screen istaking. all the :space current. ,The sudden drop ge-Jf; is .equivalent to the 1 changey 0.,-.d in Waveformff-(Figure 3.) i. ze. .when anodeccur.- rent commences. yto `flow, While. the period-Jael is 4equivalent vto the portion .d--e `o f waveform- 2. In instance; the .instantpf change. j;-Ic isf controlledv by the. .setting of potentiometer, .P9 in similar manner to the potentiometer- `PlA aas.- sociated with valve V1, and can bearranged? to take placeat any instant .over .the .time :period ofthe .levell b-cotwaveforml (Figure 3);. :The waveform 3. thus developedatthe anodey .offfVB is vfed bywaysof condenser C34. vto the .suppressor grid of-.a` furtherpentode valve VII,.to be.1 described'later.

Thetsameigc; Pi. Snvtaveform, I (Figure) is further applied-'to thecontrol grid ot athird pentode valve -V arranged in similarmanner to-valve V8 and the waveform, shotvn` at 4.1(Figure- 3) -developed=-=at its anode isapplied .bymay @condenser-C33 -to-thesuppressorgrid of valve VII. -Inthis -instance the instant of change 1re-0,; equivalent -tochang-eA g'--lcof Waveform. A.12, is adjustable by potentiometerPI-t to occur at .any desired-instant over the timeperiodA of the level d-e of-vvavetornrZJ (Figure 3) To' thej-control grid oi`--pentode valve VH1 is applied' the A250 C; P. S. squarewaveformsimilar to that shown at I (Figure 3) butflSO'Y-degrees out of phase therewith. This is conveniently effected by deriving Waveform I- from the anode and this further Waveform from the .screen grid of a valve in the valve circuit VI. Valve; ID'is arranged in similar manner to valves V8,ai1'd V9, and, accordingly there is developed atitsanOde a Waveform as shown at 5 in Figure-.3. Inthis instance, the instant of thel sudden .drop r--s, equivalent to the changes :i--lc and n-o of waveforms 3 'and 4, is controlled by the settingof potentiometer P13 and due to the 180 degrees phase displacement of the input wave, occurs .during the time of the level f-g of waveforrn2 (Figure 3) i. e. during the time of the lowermost trace on the indicator tube T. The output Waveform is fed from anode of CII] by Way4 of condenser C32 to the-suppressor grid of valveVII, in parallel with the outputs from valves V8 and-V9.

Valve VII is arranged as a transitron flipflop oscillator` in substantially similar manner to valves V'I--VIII but, by suitable values of feed back capacities and associated leal; resistances, is-arranged-to have` aconsiderably shorter time cycle ofoperation. The duration of each time cycle is adjustable in similar manner to the earlier valve, by means of potentiometer PIII'.

The capacity of each condenser C32, C33 and C34 is so chosen, With respect to the leakage resistance path RII and PIII therefor, that differentiation of theV various input waveforms shown at 3, 4 vand-5 (Figure 3) takes place-with the result that the waveform 6 (Figure 3) is applied to the suppressor grid of VI'I.r This waveform provides short positive-going pulses at the instants yof positive-going swing of any of the` anodes of valves V8, V9 or VIIII and similar shortnegative-going` pulses u, andy w (Figure 3.*Waveform'6) :at each .of the `negative-go-y ings'wings... Y 1; l'. y' YEach negative-going pulser u; 'u and'w will 0perate to cutoff anode current in the valve thereby increasing thescreen current. and lowering the screenfpotential and by a precipitateaction similar to that` previously. described Vwith relation to .valveV'I will causethegenera'tion at the screenof VII, of a negative-going square pulse for each negative-goinginput. pulse," as shown at 'y and a of waveform 'I ..(Figure` 3). The'positive-going pulses of the input, waveform 6 (Figure 3) are renderedr ineffective by suitable arrangement ofthe standing potentialsv of the valve electrodes. 1

The Waveform I (Figure 3) thus vprovided :at the screen of VII is fed from a potential'divider network by way of condenser CIS tothe `cathode of the indicator tube .T where it causes brightening of the traces at instants determined bythe position of :the negative-.goingportions 'y and e to form the afore-mentioned strobe marker portions. The portion ,1occurringwith in the time of the length b--c-rof. Waveform 2 will occur at an adjustable position alongjthe stepped portion of the iirst trace, the second portion iu, coming within the time of the length d-e of waveform 2 will occur at an adjustable position along the remainder and central portion of the rst trace while the portion z occurving within the length ,f-g of waveform I ywill trigger voltages provided'from the divider network DVI-r-,DVI'I through diode V2.v Simultaneously with operation of switch STI', the requisite component value alterations are made within the saw-tooth generator circuit V3 whereby a steeper-slope saw-tooth voltage of appropriate amplitude to span the indicator tube and commencing at the leading edge of the negative-goinginput,

is ldeveloped for each of the negativepulses.- Y In this way three higher-speed time-bases are substituted for the previous main timeebase, each providing a greatly magnied version of thesmall portion of the main time-base selected by its associated strobe marker. As both input signals and the timing marks derived from the oscillator VC continue to be displayed'in their correct relationship to one another, greatly increasedaccuracy of reading of the position of a signal with respect to the vtiming marks is-possible. At the sametime'switch SSI is altered'to` decrease .the spacing between the traces and so facilitate reading by an alignment method described ,laten The manner of operating the mobile craft apparatus is described in my copending application Serial No. 527,018. to which reference should ,be made. Briefly to obtain a x the main trace as shown in Figure 4, is first put into use by operation of switches SSI and STI and the received sig-'- .nals caused to drift alongv the y,traces by suitable Vadjustment of the oscillator VC .to' provide a hor-'- "until the'A and. B station signalsv are-n 'the Atop trace .with 'the A station pulse located on the steppedfportion. as shown at A and rB in Figure 4.

This automatically.placesthe furtherA and C station.:signals. on, the. allotted lower ltrace as shown `A and Cl in Figure 4. The oscillator, VC is 'then adjustedto obtain synchronismswhereby the received signals remain stationary. -A preliminary reading is then taken of the positions of the A,'B and C signals with respect to the 15 kc./s. and 1.5 kc./s. timing marks visible, using the 15 kc./s. marks as unit intervals and the 1.5 kc./s marks to facilitate counting by grouping intolOs. For'example in Figure 4 using the first 1.5 kc./s. mark yas zero, the A reading will be between -l and +2, theAB reading between +7 and` +8 and the C reading between +35 and +36 (the lower trace being regardedas a'continuation of the upper). 1

The three "strobei marker portions are now moved along the traces, by suitable adjustment of the potentiometers P9, PII and PI3 until they "straddle the A, Band C signals respectively. Switches SSI and STI are now operated to replace the main time-bases by the three high-I speed time-bases corresponding to the three selected strobe-marked positions, as shown in Figure 5, v The vtiming marks now visible are those at kc./s.- with, since the minimum length of the strobe marked portion is greater than one unit or l5 lkc/s. interval, at least one of thef15 kc./s unit interval marks as shown at P. Accurate measurement is now possible with the aid. of the sub-division of each Yunit interval into l0 parts by the 150 kc./s. marks; the readings shown in Figure 5 takingthe leading edge of each signal as an indexpoint are.A-.58, B+.'72, and C+.'92, giving totals of A-l.58, B+7.72 andrC+35.92. As described in greater detailin my'aforesaid cof pending application Serial No.5527,0l8 the nal delays-times of B and CA with'respect to A are therefore B+9.30 and ,C+37.50. By"reference to a suitable lattice chart thecraft position can nowbefound. p y f The above described manner of ascertaining the accurate decimal places .of the time-intervals although illustrating the fundamentalmethod may be shortened in practice by yaligning the A, B and C signals as shown in Figure 5by adjustment of the controls P9, PII andvPI3 andthen using the nearest 15 kc./s, mark on`the A traces as an index mark asishown by the dottedline in Figure 5 whereupon' thenal decimal figures may be read off directly bythe projection of such mark upon the lower traces. A switch; not shown, may beprovided to remove thejsignals from the traces while this is done. l The provision of the high-speed adjustablewor strobe time-bases with thecalibration of timemarkers superimposed thereon 'in conjunction with. the above `alignment. methodl nullied 'the effect ofI any slight drift in the frequency of 1the crystal controlled oscillator since,l once "the signal pulses have been aligned on the strobe time-bases, any subsequent drift in the frequency of the crystal controlled oscillator simply causes all three pulses to oat luniformly across the screen, without losing their mutual alignment or altering 4the relative positioning of the stationary timing marks along theftime-base traces. 1

While the invention lhas been rdes'cribedin'its particular application to navigation. .apparatus `for use with mobile.craft,.it will beapparent that it has application generally tocathode yray oscillograph techniquey where detailedinvestigation of a chosen portion of: a time-baserdisplayisdef sired'. w f' i" i' f 'if I claim: y j

1. A cathoderay oscillog-raph device comprising means forv producing a rst repetitive timebase, means for generating at least two marking signals at the -endof separately adjustable intervals of time after the instant which marks the commencementI ofy a scan of said time-base, means for utilising each. of said` marking signals to produce visible marking indications each separately adjustablein position along the length of said scan and means Afor generating at least two further time bases each operating at a higher scanning speed. than, said ,first mentioned timebase and each commencing respectively in synchronism with a separate one of said marking signals.

2. A cathode ray oscillograph device comprising asingle cathode ray tube, means for producing a repetitive time base deflection ofthe beam of said tube ata rstlscanning speed, means for generating amarking. signalat--the end of. anV adjustable interval. of time. after the instant which marks the commencement ofeach scan of said time base, means 'for `utilis'ingsaid marking signals to produce a visible marking indication adjustable in position along. the length of said scan and means for altering the characteristics of said time-base producing means whereby it produces a repetitive time-baseoperating ata higher scanning speed than said lfirst mentioned scanning speed and commencing its scanning movements from a chosen Zeroreference. position, each scan thereof Voccurring in synchronism with the time of occurence of said marking signals.

3. A cathode. ray oscillograph device comprising' means for producing a iirst repetitive timebase trace for displaying a repetitive applied signal waveform, means for generating at least two marking signals at the end of separately adjustable intervals of time after fthe instants which mark the commencement of each scan of said iirst time-base, means for utilising each of the series of said marking signals for producing separate visible marking indications each independently adjustable in'position along the length of said first time-base scans,. means for .producing at least two further repetitive time bases each operatingat a common scanningspeed which is higher than and ysubject to the samev applied signal wave form as .said rst mentioned time-base and means `.for utilising. each of said. marking signals to control respectively the instant of` commencement of one of said. higher speed timebase. scanswhereby. they provide respectively a display tov amagnied scale of that portion of the. first mentioned time-base scans-indicatedby the related marking indication-.

4. A cathode ray oscillograph devicecomprising a single cathode ray tube,. means for producing a first repetitive time-base deflection of the beam of. said. tubefmeans, for generating at least two markingsignals at theend. of .separately adjustable intervals... of time. after the Iinstants which. mark the. commencementyof. each scan of said rst time-base, means-for utilising each of said marking signals for .producing separate vis.- ible marking indications eachv independently ad.- justable in position. along the. length ofsaidiirst time-base scans. means for producing. at. least two. further` repetitive time-bases. each operating atV a common. scanning speed. which ishigher than and which. replaces said first. mentioned time-base and means. for utilising each.. of said marking signals? to. control. respectively the instant or commencement. of one. ofsaid higher 10 speed time-base scans whereby theyy provide respectively an alternative display ata magnied scale at that portion of the iirst mentioned timebase scans indicated by the related marking in. dication.

5. A cathode ray oscillograph device comprising a single cathode ray tube, means for producing a repetitive time-base deflection of the beam of said tube ataiirst scanning speed, means for generating two separate marking signalsat the end of separately adjustable intervals of time after the-instants which mark the commencement of each scan of. said first time-base, means for utilising said marking signals for producing two Separate Visible marking indications; each independently adjustable in position along ythe length of said rst time-base scans, means for altering the characteristics of said time base producing means whereby it provides time-base scans operating ata higher scanning speed than said first mentioned time-base, means for utilising said marking signals to control theinstant of commencement of said higher speed. scans and means for spacially separating. the higher-speed scans controlled by one of said marking signals from those controlled by the other marking signal so as toprovide a side-by-sidedisplay to `amagnifled scale of those portions of the iirst mentioned time-base scans which are indicated byA said mark-ing indications. i

6. A cathode ray oscillographv device. comprising means for .producing a -rstrepetitive timebase for displaying. a repetitive applied` signal input at the device,.means for generating at least two pulse-form markingsignals at the end. of separately adjustable, intervals of time after the instants which. mark they commencement of each of the scans of said rsttime-base, means for applyingy the separate vseries of said` marking. signals to. the cathode ray tube of said oscillograph device to producevisible marking indications each independently adjustable in. position along said first time-base, means for producing. atleasttwo further time-basesV each operating at. a scanning speed which. isv higher than said. first time-basey means for applying said separate series of marking signals to control said further time-base producing means whereby the scans thereof each commence atv aftime. coincident with that of the beginning of. one of said marking signals, means for spacially` separating` the further time-base scans controlled by one. series ofmarking sig.- nals fromthe. further time-base scans controlled bythe other series of. marking signals and means for applying the repetitive appliedsignalinput to cause the separate display of. thatportion-of. the information conveyed therebywhich is. coincident in time witheachk of saidfseries of marking signals on said higher speedv time-bases.

7. A cathode kray oscillog-raphvdevice comprising a cathode ray tube having a fluorescent screen, means for producing aV repetitive timebase for displaying arepetitive applied signal input, means for` providing aI seriesof -timingfsignals occurring at pre-determined instants vafter the commencement of. each scan of said repetitive time-base and in lockedtiming relationshipto the instant which marksy the commencement of each of said scans, means for. applying said timing signals tothe cathode raytube-tol-cause-visible timingv mark-ings onv said time-base scans, means for generating fat-least two-marking signal pulses at the end of separately adjustableintervals. of time after the. instantof commencement of each scan of said.time.base,-means for api- 11 plying the separate series of said marking signal pulses to said cathode ray tube to produce visible marking indications each independently adjusta- 'ble in position along said time-base scans, means for producing at least two further time-bases operating vat a higher scanning speed than said first time-base, means for applying the separate series of said marking signals to control said further time-base producing means to cause the latter to commence each of its scanning operations at a time coincident with that of one of said marking signals, means for spacially separating the further time-base scans controlled by one of said series of marking signals from those controlled by the other series of marking signals, means for applying the repetitive applied signal input to cause the respective display thereof by said further time-bases of those portions of the iirst time-base scans which are marked by said separate marking signals and means for applying said timing signals also for display by said further time bases.

8. A cathode ray oscillograph device comprising a single cathode ray tube, having a fluorescent screen, means for producing, a repetitive linear time-base deflection of they beam of said tube, means for applying a repetitive` signal input to cause deflection of the tube beam at right angles to the time-base scanning direction, means for vproducing a, plurality of pulsed-form timing signals occurring at predetermined instants after the commencement of `each scan .of said timebase and in locked timingrelationship to such commencement,` means for applying said timing signals to cause intensification of the tube beam for display on said time base in additionto the applied signal input, means for generating a pulse-form marking signal at the end of an ad- -justable interval of time after the instants which mark the commencements of, each of thescans of saidtime-base, means for producing as an alternative to said first time-base, avfurther linear time-base deiiectionvof said tube beam at a scanning speed whichis higher than that of said iirst time-base deilection, means for applyingeach of said marking signals to cause an intensication of said tube beam so as to provide a'l display indication adjustable in position along said rst time-base and means for, controlling the operation of said further time-base by said marking signals to cause said further time-base to commence operation at altime coincident with that of the occurrence of the related control marking signal and means for' applying said repetitive signal input and said timing signals for display by said further time-base.

9. A cathode ray oscillograph device for displaying a repetitive applied input-waveform comprising a cathode ray tube, time base generating means for causing a repetitive scanning motion of the tube beam, said time-base generating means being controlled as to the commencement of veach of its scanning cycles by the application thereto of a controlling signal and being provided with means whereby the scanning speed imparted to the tube beam thereby may be at either a lower or a higher value, a stable frequency oscillation generator, means for deriving from the output of said oscillation generator a pulsed control waveform whose frequency is of the same order as that of the repetition frequency of the applied input-waveform, means for applying said control waveform to lsaid time-base generatingy means when in its 'lower scanning speed condition `fory controlling the scanning cycles thereof so as to provide a timepbase for displaying ra major part of the repetitive input-waveform, means controlled'by said control waveform for generating a further pulsed Waveform whose component pulses each occur at` the, end of a predetermined and adjustable time interval after the Yrelated pulse of said control waveform, means for applying said further pulsed Waveform to said cathoderay tubeso as to provide a marking indication adjustable in position along the length of said lower speed time-base scans and means for applying said further pulsed waveform to said timebase generating means when in its higher' scanning speed condition so as to provide an alternative vhigher speed time-base for displaying that part of the repetitive input-Waveformuwhich is indicated by said marking indication on the lower speed time-base. y

10. A cathode ray oscillograph device for displaying arepetitive applied signal comprising a cathode ray tube, time-base generating means for causing a repetitivelinear scanning motion of the tube beam, said time-base generating means being controlled as to the commencement of each scanning cycle thereof by the application thereto of a Ycontrolling pulse signal and being provided with means whereby the scanning speed imparted to the tube beam may be aty either a lower or a higher value, an adjustable frequency oscillation generator, means for deriving from the output of said oscillation generator a pulse controlled waveform Whose frequencymay be adjustable to coincide .with that of vthe repetition frequency of the applied input signal, means for applying said control Waveform to said time-base generating means when the latter` is in its lowerA scanning speed condition so4 as to provide a time-base for displaying a major Ypart of each cycle of the repetitive applied signal, means controlled by said control waveform ,for generating a further pulsed waveformwhose component pulses each Aoccur at the endof a predetermined and adjustable interval of time ,after the related pulse of said control waveform, means for applying said further pulse waveform to van electrode of said cathode ray tube so as to cause an intensification of the tube beam during `the time of each pulse ,thereof andthereby tojprovide a brightened marking indication adjustable in position along the length lof said lower speed time-base scans and vmeans for applying said further pulsed waveform to said time-base generating means when the latter is in its higher scanning speed condition so as to provide an alternative higher speed time-base for 'displaying to a magnied timing scale that rpart of the applied input signal waveform which Vis indicated by the brightened marking indication on said lower speed time-base.l y

11. A cathode ray oscillograph vdevicei'or displaying a repetitive applied input-Waveform comprising a cathode ray tube, time-base generating means for causinga repetitive scanning motion of the tube beam, said time-base generating means being controlled as to the commencement of each of its scanning cycles by the application thereto of a controlling signal and being provided with means whereby the scanning speed imiparted to the tube beam thereby may be at eithera'lower or a higher value, a stable frequency oscillation generator, means for deriving from the outputof said oscillation generator ya pulsed control waveform whose frequency is of the same Order as that of the repetition frequency of the applied input-waveform, means for applying said control waveform to said time-base generating means when in its lower scanning speed condition for controlling the scanning cycles thereof so as to provide a timebase for displaying a major part of the repetitive input-waveform, means for deriving a series of timing signals occurring at predetermined instants after each pulse of said control waveform, means for applying said series of timing signals to the cathode ray tube to cause the display of timing marks on said time-base scans, means controlled by said control waveform for generating a further pulsed waveform whose component pulses each occur at the end of a predetermined and adjustable time interval after the related pulse of said control waveform, means for applying said further pulsed waveform to said cathode ray tube so as to provide a marking indication adjustable in position along the length of said lower speed time-base scans and means for applying said further `pulsed waveform to said time-base generating means when in its higher scanning speed condition so as to provide an alternative higher speed time-base for displaying that part of the repetitive input-waveform and the associated timing marks which are indicated by said marking indication on the lower speed time-base.

12. A cathode ray oscillograph device for dis playing a repetitive applied signal comprising a cathode ray tube, time-base generating means for causing a repetitive linear scanning motion or" the tube beam, said time-base generating means being controlled as to the commencement of each scanning cycle thereof by the application thereto of a controlling pulse signal and being provided with means whereby the scanning speed imparted to the tube beam may be at either a lower or a higher value, an adjustable frequency oscillation generator means for deriving from the output of said oscillation generator a pulse controlled wave-form whose frequency may be adjustable to coincide with that of the repetition frequency of the applied input signal, means for applying said control waveform to said time-base generating means when the latter is in its lower scanning speed condition so as to provide a timebase for displaying a major part of each cycle of the repetitive applied signal, means for deriving a series of timing signals occurring at predetermined instants after each pulse of said control waveform, means for applying said series of timing marks to the cathode ray tube to cause momentary intensication of the tube beam to provide a series of brightened timing marks on said time-base scans, means controlled by said control waveform for generating a further pulsed waveform whose component pulses each occur at the end of a predetermined and adjustable interval of time after the related pulse of said control waveform, means for applying said further pulse waveform to an electrode of said cathode ray tube so as to cause an intensification of the tube beam during the time of each pulse thereof and thereby to provide a brightened marking indication adjustable in position along the length of said lower speed time-base scans and means for applying said further pulsed waveform to` said time-base generating means when the latter is in its higher scanning speed condition so as to provide an alternative higher speed timebase for displaying to a magnified timing scale that part of the applied input signal waveform and the associated timing marks which are indicated by the brightened marking indication on said lower speed time-base.

13. A cathode ray oscillograph device as recited in claim 9 in which means are iprovided for varying the time duration of each of the pulses of said pulsed control waveform.

14. A cathode ray oscillograph device as recited in claim 10 in which means are provided for varying the time duration of each of the pulses of said pulsed control waveform.

ROBERT JAMES DIPPY.

REFERENCES CITED rThe following references areof `record in the iile of this patent:

UNITED STATES PATENTS l Date 

